U.S. patent application number 14/395865 was filed with the patent office on 2015-04-30 for exoskeleton arm having an actuator.
The applicant listed for this patent is COMMISSARIAT A L"ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES. Invention is credited to Philippe Garrec, Yann Perrot, Dominique Ponsort, Aurelie Riglet.
Application Number | 20150119998 14/395865 |
Document ID | / |
Family ID | 46826696 |
Filed Date | 2015-04-30 |
United States Patent
Application |
20150119998 |
Kind Code |
A1 |
Garrec; Philippe ; et
al. |
April 30, 2015 |
EXOSKELETON ARM HAVING AN ACTUATOR
Abstract
The invention relates to an assist arm intended to be fitted on
an exoskeleton, having a mounting plate (2) carrying a drive member
(20), a shoulder segment (4) articulated on the mounting plate, an
arm segment (6) having a proximal end articulated on the shoulder
segment, a forearm segment (8) having a proximal end articulated on
a distal end of the arm segment, an actuating cable (27) driven by
the drive member and forming two strands (27a, 27b) which extend
parallel to the first axis in order to pass through the first
articulation and to wind around a receiving pulley (30) which is
mounted in a rotating manner about the second axis and which
rotates as one with the arm, and connecting means (31, 32, 33)
coupled between the shoulder segment and the forearm second segment
and arranged such that a flexion of the arm segment causes a
concomitant flexion of the forearm segment.
Inventors: |
Garrec; Philippe;
(Gif-Sur-Yvette, FR) ; Perrot; Yann;
(Sainte-Genevieve Des Bois, FR) ; Ponsort; Dominique;
(Bievres, FR) ; Riglet; Aurelie; (Dammaries Sur
Loing, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
COMMISSARIAT A L"ENERGIE ATOMIQUE ET AUX ENERGIES
ALTERNATIVES |
Paris |
|
FR |
|
|
Family ID: |
46826696 |
Appl. No.: |
14/395865 |
Filed: |
May 28, 2013 |
PCT Filed: |
May 28, 2013 |
PCT NO: |
PCT/EP2013/060918 |
371 Date: |
October 21, 2014 |
Current U.S.
Class: |
623/57 |
Current CPC
Class: |
A61F 2/582 20130101;
A61F 2/585 20130101; A61F 2002/5093 20130101; A61F 2002/5066
20130101; A61F 2002/7862 20130101; A61F 2/54 20130101; A61F 2/78
20130101; A61F 2002/5038 20130101; B25J 9/0006 20130101; A61F 2/58
20130101; A61F 2/68 20130101; A61F 2002/5018 20130101; A61F 2/581
20130101; A61F 2002/5081 20130101; A61F 2002/546 20130101; A61F
2/70 20130101; A61F 2002/543 20130101; A61F 2002/5096 20130101;
A61F 2/583 20130101 |
Class at
Publication: |
623/57 |
International
Class: |
A61F 2/54 20060101
A61F002/54 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 4, 2012 |
FR |
1255177 |
Claims
1. An assist arm intended to be fitted to an exoskeleton,
comprising: a mounting plate (2) carrying a motor component (20); a
shoulder segment (4) articulated on the mounting plate by means of
a first articulation (3) about a first axis (X1) which is
substantially vertical during use; an arm segment (6) having a
proximal end articulated on the shoulder segment by means of a
second articulation (5) about a second axis (X2) which is
substantially perpendicular to the first axis; a forearm segment
(8) having a proximal end articulated on a distal end of the arm
segment by means of a third articulation (7) about a third axis
(X3) which is substantially parallel to the second axis; the assist
arm being characterized in that it furthermore comprises: at least
one actuation cable (27) driven by the motor component and forming
two strands (27a, 27b), which extend parallel to the first axis so
as to pass through the first articulation and be wound around a
receiving pulley (30) which is mounted so as to rotate about the
second axis and is linked in rotation with the arm; connecting
means (31, 32, 33) which are attached between the shoulder segment
and the forearm segment and are arranged so that flexion of the arm
segment leads to concomitant flexion of the forearm segment.
2. The assist arm as claimed in claim 1, wherein the motor
component (20) is associated with a cable actuator (22) which
drives a drive cable (23) tensioned between two first pulleys (23,
24) mounted so as to rotate on the mounting plate (2), the
actuation cable (27) being for its part attached to two second
pulleys (25, 26) respectively linked to the first pulleys (23, 24)
and having a diameter less than a diameter of the first
pulleys.
3. The assist arm as claimed in claim 1, wherein the forearm
segment comprises a distal end provided with a handrest (9).
4. The assist arm as claimed in claim 1, wherein the connecting
means between the shoulder segment (4) and the forearm segment (8)
comprise a coordination pulley (31) concentric with the second axis
(X2) but fixed on the shoulder segment, a drive pulley (33) mounted
so as to rotate about the third axis (X3) while being linked to the
forearm segment, and a coordination cable (32) wound with strand
crossover on the coordination pulley and the drive pulley.
5. The assist arm as claimed in claim 1, wherein the forearm
segment (8) comprises two subsegments (8a, 8b) articulated to one
another by means of a fourth articulation about a fourth axis (X4)
which is substantially perpendicular to the third axis (X3).
Description
[0001] The invention relates to an exoskeleton arm having a single
actuator, which may advantageously be fixed to the dorsal part of
an exoskeleton.
BACKGROUND OF THE INVENTION
[0002] There are various known assist arms which can be fitted to
exoskeletons, and can be used in particular for lifting loads from
below, for example a sack of sand or a patient. In general, these
arms have shoulder, elbow and wrist articulations that are
associated with respective motorizations, which makes the assembly
heavy and complex. Furthermore, the motorizations are often in the
form of transverse motors extending in continuation of the axis of
the articulation, which entails significant encumbrance. In order
to limit this encumbrance, it is therefore expedient to restrict
the load which can be lifted, or to increase the down-gearing ratio
between the motor and the driven segment, which tends to reduce the
transparency of the articulation. This drawback may be partially
overcome by torque feedback, but this requires the use of a torque
sensor, making the solution less reliable, more complex and more
expensive.
[0003] There are other solutions, for example lifting components
which can be fitted to an exoskeleton and which comprise spring
balancing instead of an actuator. Such a component needs to be
adjusted beforehand for a given load, which greatly limits the
range of its use.
OBJECT OF THE INVENTION
[0004] The object of the invention is to provide a simplified
assist arm for an exoskeleton, the compactness of which makes it
easy to integrate it with an ambulatory exoskeleton such as the
HERCULE exoskeleton from the company Rb3d.
SUMMARY OF THE INVENTION
[0005] With a view to achieving this object, an assist arm intended
to be fitted to an exoskeleton is provided, comprising: [0006] a
mounting plate carrying a motor component; [0007] a shoulder
segment articulated on the mounting plate by means of a first
articulation about a first axis which is substantially vertical
during use; [0008] an arm segment having a proximal end articulated
on the shoulder segment by means of a second articulation about a
second axis which is substantially perpendicular to the first axis;
[0009] a forearm segment having a proximal end articulated on a
distal end of the arm segment by means of a third articulation
about a third axis which is substantially parallel to the second
axis. According to the invention, the assist arm furthermore
comprises: [0010] at least one actuation cable driven by the motor
component and forming two strands, which extend parallel to the
first axis so as to pass through the first articulation and run
around a receiving pulley which is mounted so as to rotate about
the second axis and is linked in rotation with the arm; [0011]
connecting means which are attached between the shoulder segment
and the forearm segment and are arranged so that flexion of the arm
segment leads to concomitant flexion of the forearm segment.
[0012] Thus, with the aid of a single motor component mounted on
the mounting plate (and therefore positioned on the operator's back
when the mounting plate is attached to the exoskeleton), it is
possible to lift loads using the forearm. The assembly is very
compact, and the motor component can be placed on the mounting
plate, and therefore on the operator's back, so that it does not
interfere with the operator's vision or the range of the movements
of the assist arm.
[0013] The directions during use refer to articulation directions
when the exoskeleton is being worn by an operator, the latter
having an arm which cooperates with the assist arm in a resting
position along the body.
[0014] According to a particular embodiment, the forearm comprises
two subsegments articulated to one another by means of a fourth
articulation about a fourth axis which is substantially
perpendicular to the third axis. This arrangement allows free
lateral movement of the end of the arm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention will be better understood from the following
detailed description of a particular embodiment with reference to
the figures of the appended drawings, in which:
[0016] FIG. 1 is an outline diagram of the assist arm according to
the invention;
[0017] FIG. 2 is a view of an exoskeleton fitted with the assist
arm of the invention and worn by a user.
DETAILED DESCRIPTION OF THE INVENTION
[0018] With reference to the figures, the assist arm 1 of the
invention comprises firstly a mounting plate 2, which carries a
first articulation 3 making it possible to articulate a shoulder
segment 4 about a first axis X1 which is vertical during use. The
mounting plate 2 is advantageously equipped with means for
attachment to the dorsal part of an exoskeleton 100, or at least a
support structure worn by an operator.
[0019] The shoulder segment 4 carries a second articulation 5
making it possible to articulate the proximal end of an arm segment
6 about a second axis X2 (here seen end-on) which is substantially
perpendicular to the first axis X1. The distal end of the arm
segment 6 carries a third articulation 7, which makes it possible
to articulate the proximal end of a forearm segment 8 about a third
axis X3 (here seen end-on) substantially parallel to the second
axis X2. The forearm segment 8 has a distal end which carries a
handrest 9. Here, the forearm segment 8 is divided into two
subsegments 8a, 8b, which are connected together by a fourth
articulation 10 making it possible to articulate the two
subsegments to one another about a fourth axis X4 which is
substantially perpendicular to the third axis X3.
[0020] The assist arm 1 of the invention is provided with a motor
component 20 carried by the mounting plate 2, here an electric
motor, capable of driving a first cable 21 or drive cable by means
of a cable actuator 22. The drive cable 21 comprises a strand
tensioned between two first pulleys 23, 24 mounted so as to rotate
on the mounting plate 2. The first pulley 24 is provided here with
a tensioner 25 for maintaining a tension in the drive cable 21. The
first pulleys 23, 24 are linked in rotation respectively with
second pulleys 25, 26 having a diameter less than that of the first
pulleys 23, 24. Attached to the second pulleys 25, 26, there is a
second cable 27 or actuation cable, which, with the aid of two
return pulleys 28, 29 mounted so as to rotate on the mounting plate
2, form two strands 27a, 27b which extend parallel to the first
axis X1 while passing inside the first articulation 3, which is
hollow. The two parallel strands 27a, 27b then separate and run
around a receiving pulley 30 mounted so as to rotate about the
second axis X2 while being linked in rotation with the arm segment
6.
[0021] Thus, when the electric motor 20 is operated, it causes
movement of the drive cable 21 in one direction or the other,
thereby causing movement of the actuation cable 27, which induces
flexion of the arm segment 6. Passage of the strands 27a, 27b of
the second cable through the first articulation (which is free)
allows free rotation of the shoulder segment without causing
flexion of the arm segment 6. The use of two cables wound around
pulleys with different diameters allows step-down torque
conversion.
[0022] The arm of the invention is furthermore equipped with
connecting means making it possible to generate flexion of the
forearm segment 8 in response to flexion of the arm segment 6. In
the present case, these means comprise a coordination pulley 31
fixed to the shoulder segment 4 concentrically with the second axis
X2. A third cable or coordination cable 32 is attached to the
coordination pulley 31 and, after crossover of the strands, runs
around a drive pulley 33 mounted so as to rotate about the third
axis X3 while being linked in rotation with the forearm segment 8.
By virtue of these connecting means, flexion of the arm segment 6,
caused by the motor 20, induces concomitant flexion of the forearm
segment 8 in the same direction. By varying the respective
diameters of the coordination pulley and of the drive pulley, the
amplitude of the flexion of the forearm segment as a function of
the amplitude of the flexion of the arm segment is adjusted
accurately.
[0023] Such an assist arm has several advantages. Firstly, it uses
only a single motor component, located on the operator's back. It
also makes it possible to lift a load from below. Furthermore,
actuation by a cable actuator makes it possible to position a long
motor mounted flat on the mounting plate (and therefore on the
user's back), leading to a very thin assist arm with very
transparent transmission (low inertia and friction), making it
possible to obviate feedback by a torque sensor. Lastly, the arm is
self-contained and can be removed easily from the exoskeleton.
[0024] The invention is not limited to that which has been
described above, but rather covers any variant falling within the
scope defined by the claims.
[0025] In particular, although the connecting component between the
shoulder segment and the forearm segment comprises two pulleys and
an associated coordination cable in this case, other connecting
components may be used, such as a link rod attached between the
shoulder segment and the forearm segment.
[0026] Although the actuation in this case employs a double-loop
cable actuator with two cables, making it possible to increase the
force of the cylinder with a negligible loss of energy,
single-cable actuation may be used. In this case, the cable
actuator will act directly on the actuation cable.
* * * * *